Date of Award


Document Type

Open Access Thesis


Biomedical Science


School of Medicine

First Advisor

Michelle Androulakis


Chronic Migraine (CM) is a debilitating neurological condition that occurs when the migraine frequency progresses to a chronic state of more than 15 headache days per month. The overuse of analgesic medication (MOH) is one of the most prominent risk factor of this chronification and little is known about why it is a cause. The repetitive inhibition of the Sphenopalatine Ganglion is one promising treatment that is used to treat chronic migraine. The purpose of this study is to determine if a specific pattern of disruption is present for chronic migraine, both with and without medication overuse headache, and if that disruption can be normalized after a series of Sphenopalatine Ganglion blocks. Resting state functional magnetic resonance imaging was used to analyze differences in intrinsic functional networks between CM patients with and without MOH, between each CM subgroup and age matched controls, and between a subset of CM patients before and after they received a series of SPG treatment. Three major intrinsic brain networks, including the Default Mode Network (DMN), Silence Network (SN) and Executive Control Network (ECN), were statistically less coherent with CM (both with MOH and without MOH) as compared to controls. There were also specific patterns of disruption to the intranetwork connectivity in each CM subgroup as compared to controls. After 6 weeks of treatment, overall improvements were seen in both the DMN and ECN. Our results suggest that there are underlying differences between CM with MOH and CM without MOH that may be caused by disruptions to smaller systems that exist within the SN and ECN. Additionally, in CM without MOH, a disruption to the subcallosal area within the SN may be associated with the inability to inhibit the thalamus from sending pain signals to pain processing areas, causing chronic pain. This disruption was not seen in CM with MOH patients, suggesting that there is a different disruption present which accelerates the chronification process. After six weeks of SPG block treatment, overall improvements were seen in both the DMN and ECN, suggesting this treatment can help the normalization of these networks.


© 2016, Kaitlin Krebs